Hydraulic drives for rectilinear alternating motions for reciprocating machines



Feb. 28, 1961 F. KLOPP ETAL 2,972,864

HYDRAULIC DRIVES FOR RECTILINEAR ALTERNATING MOTIONS FOR RECIPROCATING MACHINES Flled Dec. 51, 1959 2 Sheets-Sheet 1 2,972,864 HYDRAULIC DRIVES FOR RECTILINEAR ALTERNATING MOTIONS Feb. 28, 1961 F. KLOPP ET AL FOR RECIPROCATING MACHINES 2 Sheets-sheaf. 2

Filed Dec. 31, 1959 3N l/EN TURJ' United States Patent "1ce Patented Fri.

1' 2" i stroke, said rack cooperating via a pinion with the 2,972,864 ratchet wheel of the feed. As the'feed only takesplace s a F vi 7 v durin one stroke, only one of the piston rods needs fi fig g to co perate with the ratchetwheel. v,

QQINES 1 1 5 Still another object of the'invention is to provide for r 7 larger machines a hydraulically operated advance motor Friedrich Klopp, Friedrich .Klopp, In, a Fliedhelm in which the discharge'ducts for the oil expelled from v Lessenich *sofingen'waldwGemmny asslgnors the reversing valve are connected with the cylinder of w solmgeu'wam" Ge-rmany a the control val ve for the reciprocating movement of the me 1 i a it i 10 machine which-is actuated by stop pistons one of the 7' Filed Dec. 31, 1959, SeriNo. 863,208 I I discharge {ducts'being connected with the feed motor via H i i the cylinder of the control valve and the cylinders of the Clam]. s applicpafidnrcrmanyihni I feed direction pistons, while the other pressure duct'com- 5 Claims. (0560-52) I I v municates with throttle means. p #Two' embodiments of the invention are shown'sche- V invention relates to hydraulic dI'iVeSi-fOlT-i rectimatical lyby wayroftexamplesy In the drawings;

linear alternating motions for reciprocating machines, i 1: Shows a Switching diagram with n emulation p y machine tools h a P p 'conllectedwith of' the -feed by mechanically connecting the reversing the cylinder chambers of the operating cylinder, the diso t l v l e ith the ratchet means, I 7

charge quantity of which may be infinitely adjusted by FigureqA .1 1 View gof-nth ge e h i means of a control'element through a-neutral position sociated components, nd f p, 1 v f :1 to areverse direction of flow,- and providesfurther imv-Fig -12' Sh0ws"a"sdiagrami-fo rla,'hydraulicconnection movements f theidrive according eg p m ofthe reversing control valve-with the feed motor. application SBLVNOQ; 730,567, HOW PateHt NO.- 2,928j,2 44, sh' wn in kltcon-csponds to the dated March Thewldef p t ppl n illustrated arrangement of the above mentioned-older relat'esto a'drive of this type in which the control-ele- 1 n o i go 'Fig 1; drive, f nd. merit of the infinitely adjustable pump (generator) may be tioningas f llo s; reciprocated between two extreme Positions d y The generator 62: is sucking oil out of the container p y a reversing control valve of he Piston 22 through the duct ZI'and'feeds the pressure oil through slide yp which is actuatedyby P I P- if 111 the'ducts 23, 24," to a precontrol valve'K3 and-through this arrangement the reversing control valvewhicl'i is V d t '25 to the reversing valve K4, thereby moving the making equal strokes towards both Sides f neutral reversing valve K4 into its left hand position. In this Position corresponding) a discharge Volume of Zero end positionthe pressure oil from the generator G2 may and the control element of the pump are guided with guide pins in'a guide way dfi'a commo'n crank the pivotfiow via acorrespondingly switched path to the duct 26.

In'this'end position of the reversing valve K4 the presing pointof which is adjustable 5 Spindle Varying s s'ure oil'from' generator G1 flows through the ducts 27, r

"t e movements "which equal magnihidewwards 2 es -the switchvalve Kama duct;3 into the aperboth sides of the neutral position. Furthermore; accord-i iating cylinderand moves the operating piston K1 downn 1 fl fi p i l ip fl wardly; "The oil discharged by the piston Kl returnsadjustment of the control pump is coupled withthe pivotthrough the duct 31; the switch valve" K2,;the ducts in point the ra s t te i m t f 32;33 and 34 to the generator G1. Flush oil enters the the-p p control valve always-corresp nd to a pm working circuitthrough'the duct 26. Prior to this the -P9 1- dil '9 h Q 1i Q P P- d g o I surplus oil is leaving th'e'ci'rcuit through the dtictBS another feature oftheabove mentionedolder patent Yap (this is achieved by the'im possibility of the "flush oil: to plication the control pump is connected in such a way that, besides; actuating the reversing control valve and valve"K'4, thezducts-66, 37, acounter pressure valve "V2 flushing th'e 'eirculating system, 'itlmay' also serve as ;an'd duct"38'-i nto' the supply container l2 2.' The valve drive of--.an1'advance=motor st-he retur'n of which 1s 'con- 'VZ's'ets'up a smallbackpressurer The operating piston nected with a proportioning valve the adjustable piston -K1 nowmove's downwardly working in a "'closed;ci-rcuit stroke of which .definesgthe magnitude 'of the feed.

fiow against the stream) and1fiows'via the reversing.

ofthegene'ratorgGlg The rigidity ofr'fthe drive and the One object of the invention is "to provide a further transmissiono'f heat out of the circuit is secured' hvth'e -improv m ntvof. th dvnce. e utwLinth t-the, actuati n pressure flushing ofthe output otgen ato iqz. I, of the1feed switchingkdevice simultaneously takes place i The switching'of the operating "piston K1 "is in fthis with the switching of the rfivs i sing QPUTQ1 ya1ve y case-achievedby electrical means Thelimit stop A1, "'ei'thera direet.,mechanical connection}; being either connect dwith'the-piston rod 2of"thework- "ing piston'Kl orthe nia'chinejelementto berdri'ven, oper- 1mins right hand position. When the operating piston the operatingitime as compared 1: in, v n 'j-M'Sisenergized. .The reversingymove'ment of the piston .accordingzto?.the above ment oned patent pplication as' I of the precontrol valv'e K3 may-belachievedg in" any ecordingwto;this:;the'sadvance:.maymotiabe ctuated' be- 'otherway as well.

fore the-reverse switching; is completed.

fi th 'n ention isto provide a me-' from the duct '24'via the preco'ntrolj valvefK3 and duct 5 the'riglit', as the oil is discharged tram thegduet zssm ates the switch T1 whereby theTnagnetM l is energizled, I thereby moving the piston off'th'e precontroli valveK3 '.i-K1 -'meves "irran' 'opposite direction the limit "stopjAZ actuates' the switch T2 by which the associated magnet" The; oil-.; discharged-: by"v the generator G2 new" iiows i '32[to .ther reversing valve K4 which will move towards fip si ast e.p ea Ki'er n ,duct mm rand 421tofthe'c6ntainer' 22; In the opposite position of the" e 92;; r am-we he re en rate I ntr'ol piston valvwith stroke.

the duct 39 via .the duct 53 which is connected with the.

duct 41. A slightly preloaded backpressure valve V3 ensures that the control ducts are filled with oil. Simultaneously with the switching .of the reversing valve K4 the generator G1 is moved by the crank 9 into the op,- posite position of eccentricity. The pressure oil which previously had been flowing .to the duct 27 and returned via the duct 34 continuously decreases during this operation. In the neutral position the stream of pressure oil momentarily ceases to flow entirely, and upon exceeding the neutral position towards the OPPQSite position of eccentricity. the pressure oil flows to the duct 34 and returns .via the duct 27. The direction of movement of the operating piston K1 .is thereby reversedandpovv directed upwardly. Contrary to the above mentioned older patent application the piston of the reversing valve K4 is pro,- vided with piston rods 200 and 201 on both ends, the length of which are so that they extend out of the cylinder 7 when the piston of the reversing valve 4 is in its dead end positions. In addition to this the piston rod 201 is extended still further beyond this. This extension forms a rack 202 which engages a pinion 203 of the ratchet wheel 204. *When the piston of the reversing valve K4 is switched from the left hand position, as shown in the drawing, to the right hand position, the pinion 203 is rotatedby the rack 202, and thereby .the feed (shown partially at 204a) of the slide, ram or the like of the machine tool is actuated during the return stroke of K1, while during the movement of K4 from right to left the dog of the ratchet wheel operates in the known manner.

The switching diagram shown in Fig. 2 corresponds to the diagram of Fig. 3 of the above'mentioned older patent application with the only difference that, accord- ;ing to this invention the feed valve may be abolished.

a e-at According to the invention the return duct 1 04 of the reversing valve K4 is connected to the cylinder 206 of theprecontrol valve K3. The oildischarged from the reversing valve K4 when moved from right to left leaves thecylinder 206 at 207 and flows intotheduct 127. The duct 127 is connected with the feed motor VM via-the cylinders of the feed direction pistons K9 and. K7. .The other discharge -duct 93 of the reversing valve K ii sconnected at 208with the cylinder 206 of the precontrol valve K3; During the movement of the reversing yalve K4 from right to left, as illustrated in the drawing, the gear purnpZP feeds oil through the .duct 91 to the cylinder of the switch valve. K2 and thence via the duct 105 to the cylinder 206 and via the duct .9 :to the right side of the reversing valve K4. When switching the reversingvalve K4 to movefrom left to right the oil discharged into the duct 93 flows vvia i hthis duct 93 through port 208'into the .cylinderj206,

and thence flows throughtlie duct 106 directly to the throttle DR, and from there .via the duct 107 into the container '22. The oil discharged by the, gear pump Z1 is fed throughthe cylinder fof the switchyalve K2 into the duct 105, and thence flows via the cylinder 206 into the duct 104thus effecting the switchingof thereyer'singValve K4. 7 i t The following is. a listoficomponentsin the emb diactuating a table; slideor the like. Fl-Thegreater piston surface of K1.

- and its PiStOIl-I'Qda ZP-LA control gear pump.

9 rCr ank pivoted at 8 on K4 moving G1 and G2 through zero output position, the .control position of K4 corresponding to the zero output position of G1 and G2.

K10-Pivoting point of the crank 9.

10, 16, 17Pin, spindle {and nut for adjusting the pivot Po t of h an and hu the Pivo a eo Q 117Slide by which G1 and G2 are pivoted by pins 120,

121 and guide slots 118, 119.

12--Pin pivotally con'nectingcrank 9 with slide. 117.

K6-Piston valve for automatically adjustinglspindle 16 by gearing 54. i i

DR-Throttle, simultaneously adjusted with spindle'16 by pair of gears 55 thus regulating the output of ZP proportionally to the outputs of G1 and G2.

K3 Precontrol piston valve for K4, controlling ZP to deliver via duct s .91 or-105 into ducts 03 or 104.

T1, T2Hydraulic contacts consisting of small pistons which are moved upon engagement by the limit stops A1 and A2 thus causing a displacement of an oil col.- umn by which K3 is shifted. j

KZ-Stop valve connecting or interrupting main ducts 8.5 and 86, thus controlling stop or .operation.

-'VM-Feed motor operating a spindle.

K9Piston valve for feed on or oil byconnecting or interrupting the ducts 127, 1 28. 7

K7.:Piston valve for changing the direction offe ed by connecting duct 129either to duct 130 or duct 131.

K8.Piston valve for changing the directionof feed by adjusting the volume of oil delivered by VM. The

. adjustment of the oil volume is achieved by the spindle K10-Piston valve for rapid advance. Held in its position by a spring 142,- it interrupts the delivery from ZP via duct 141 as well as the outlet from VM via duct 144. As long as K10 is pushed in VM is run- K2''-Pist0n valve for preselecting the rapid advance. In a pulled-out positionit connects duct 9115mm ZP with duct 141 to K10. In a pushed-in position as illustrated in thedrawing K10 is not affected.

Condition for equal volumes withinthe system 7 F1 :F2= (G1 +G 2) :Gl, example: F1=2/F2='1- Theleft hand position of K4 corresponds to a movement of K1 in the direction indicated by the arrow Control piston K4 is "moved to. the illustrated positionby feeding controLoil from ZP via'the ducts 91, K2, 105,f K3, "208 and 93 to K4. In the end position.

. of K4 mean flows Lviathe ducts 9 4, 96 into the ducts irnent' of Figure 2, followed by a'description'of its opera-' tion:

'Zfi-ThB annular piston .surfaceformed hy piston K1 i 31 15; 116- -Electro' motor with 2' K lri-f Piston, thepiston rodextending to-rone'side and 786-89 which are the main return ducts in this insta nce,

and flushes thesystem. with fi'esh oil.

conducted via duct 97 and K4 to thesupply container.

I y Operating oil is i e? 9. 99, 1

' The righthand position 0 .K4 corresponds 10112-17101;

.. fment'of K1 in the direction opposite that indicated the arrow.

1 Control piston; K4 is .n dvea to the righlshand' position (opposite l to that shown) by switching K310 its other 'pe t n byim n 9 nonstop A1 uatin t 11 v- 'd raulic' eontactf T1. Nowthe' control oil flows fr om ZP .Yia9 Z'. I sition of Kit 1. .3.2 2.05? 1 4 Q Q Kfl: EQ e RQ". I he oil T newsman: 112 into th'nittih duct 83 which in this instance represents the return duct and which is thereby flushed with fresh oil. Through the ducts 113, 114 operating oil flows via K4 and ducts 114, 98, 99, 100 to the container.

The adjustment of the velocity of K] for the advance and the return stroke is achieved by K6 In the illustrated position (direction of arrow) control oil is fed from ZP via duct 122 to K6 and moves the latter into engagement with the spindle 18. Handwheel 13 serves to adjust the eccentricity of the pumps G1 and G2 for the advance (operating stroke) of K1.

During the return stroke (opposite to the direction of arrow) oil is fed to G2 from where it is delivered via ducts 108, 109 to K6 whereby the latter is pushed into its left hand end position (greatest eccentricity of G1 and G2) and flows through duct 110 to the container.

Feed control Every time K1 changes from return to advance movement K4 is moved from its right hand to its left hand position by feeding control oil to it from ZP via duct 93. The oil thereby displaced flows via 205, K3, 207, 127, K9, 128, 129, K7, and 130 to the feed motor VM.

The oil discharged by VM flows via 131, K7, 132 and 133 to KS. The adjustment of the oil volume determines the number of revolutions of VM. The surplus oil not required for the movement of VM (the total discharge determines the maximum amount of feed) flows via 127a and valve V3 to the container.

During the return stroke of K1, K3 has been moved to its right hand position by means of limit stop A1 and hydraulic contact T1. In this position of K3 K8 can discharge via the ducts 133, 137, 138, K3, 105 into the container. K8 may reassume its preparatory position by moving it toward the left by means of the flushing pressure V2 via ducts 99, 139.

The mode of functioning of the entire drive corresponds to that described in the above mentioned older patent application.

What I claim is:

1. In a hydraulic drive for effecting alternating rectilinear motion, a cylinder, a piston within said cylinder connected to a driven machine member, an advance motor for said member, first and second chambers of varying volume defined by said piston, means for generating hydraulic pressure including a variable delivery pump, conduit means connecting one side of said generating means with said first chamber and connecting the other side of said generating means with said second chamber, an adjusting member movable from a neutral position in either direction for infinitely varying the output capacity of said generating pump and for reversing the flow direction thereof, a reciprocable reversing valve of the piston slide valve type having a valve cylinder and stroke of predetermined length, a precontrol valve of the piston slide valve type responsive to arrival of said piston at a definite position for causing said reversing valve to shift through said predetermined stroke, connecting means between said reversing valve and said adjusting member for causing a constant shifting of said adjusting member during the movement of said reversing valve, the position of said adjusting member atany instant being proportional to the position of said reversing valve, said advance motor being drivably connected with and operated simultaneously by the stroke of said reversing valve piston.

2. The combination according to claim 1, said piston of said reversing valve being provided with rod extensions extending on both sides out of the valve cylinder, one of said rods being provided with a rack at its end extending out of the cylinder beyond the piston stroke, said rack engaging a pinion cooperating with a ratchet wheel of said advance motor.

3. In a hydraulic drive for effecting alternating rectilinear motion, a cylinder, a piston Within said cylinder connected to a driven machine member, first and second chambers of varying volume defined by said piston, means for generating hydraulic pressure including at least one variable delivery pump, conduit means connecting one side of said generating means with said first chamber and connecting the other side of said generating means with said second chamber, an adjusting member movable,

from a neutral position in either direction for infinitely varying the output capacity of said generating pump and for reversing the flow direction thereof, a reciprocating reversing valve of the piston slide valve type having a stroke of predetermined length, a precontrol valve of the piston slide valve type, a variable delivery control pump responsive to the arrival of said precontrol valve piston at a definite position for causing said reversing valve to shift through said predetermined stroke, connecting means between said reversing valve and said adjusting member for securing a constant shifting of said adjusting member from one side of its neutral position to the other during the movement of said reversing valve, the rate of movement of said adjusting member being proportional to the rate of movement of said reversing valve, output selector means for varying the proportion of said adjusting member movement with respect to said reversing valve movement, whereby the maximum output of said generating pump may be selected, and means comprising a hydraulically operated advance motor, connected to said precontrol valve, the discharge conduits of said reversing valve being connected with said precontrol valve.

4. The combination according to claim 3, including advance direction piston slide valves, one of said discharge conduits being connected with said advance motor via said precontrol valve and said advance direction valves.

5. The combination of claim 3 including a throttle means with which the other one of said discharge conduits is connected via said precontrol valve.

No references cited. 

